HomeMy WebLinkAboutGeotechnical Feasible Study®EnGEN
' CORPORATION
GEOTECHNICAL FEASIBILITY STUDY
PRIVATE BMX TRACK
SIPKOI RESIDENCE
33239 Susan Grace Court, Temecula, California 92592
' Lot 24 of Tract 26941 — Assessor's Parcel Number: 965-220-029
Project Number: M3903 -GFS
May 25, 2010
Prepared for:
' Rick & Cathy Sipkoi
33239 Susan Grace Court
' Temecula, CA 92592
' 25759 Jefferson Avenue, Murrieta, California 92562 • Phone: (951) 834-9000 • Fax' (951)8349001
TABLE OF CONTENTS
Section Number and Title
Page
1.0
Site Suitability.................................................................................................................1
1.1
Structures..................................................................................................................1
1.2
Other Site Conditions...............................................................................................1
2.0
Site Review & Geotechnical Investigation..............................................................2
3.0
Earthwork Recommendations..................................................................................2
3.1
General......................................................................................................................2
3.2
Clearing......................................................................................................................2
3.3
Excavation Characteristics......................................................................................2
3.4
Suitability of On -Site Materials as Fill.....................................................................
2
3.5
Grading Recommendations for All Areas................................................................3
3.6
Structural Fill.............................................................................................................3
3.7
Compaction Equipment............................................................................................4
3.8
Shrinkage — Alluvium&Colluvium..........................................................................4
3.9
Keyways.....................................................................................................................4
4.0
Observation and Testing..........................................................................................4
5.0
Stability Evaluation of Cut and Fill Slopes..............................................................5
6.0
Finish Lot Drainage Recommendations..................................................................5
7.0
Supplemental Construction Observations and Testing.........................................5
8.0
Plan Review...............................................................................................................5
9.0
Closure.......................................................................................................................6
®EnGEN
CORPORATION
IMay 25, 2010
Mr. & Mrs. Rick Sipkoi
33239 Susan Grace Court
Temecula, CA 92592
' (949) 533-5515
Regarding: GEOTECHNICAL FEASIBILITY REPORT
' Private BMX Track
33239 Susan Grace Court, Temecula, California 92592
Lot 24 of Tract 26941 — Assessor's Parcel Number: 965-220-029
' Project Number: M3903 -GFS
Dear Mr. & Mrs. Sipkoi:
In accordance with your request, a representative of this firm has performed a geotechnical field
reconnaissance of the subject site to visually observe the surficial conditions and provide an
opinion of the need for a Subsurface Geotechnical Study for the proposed grading to create a
private track for BMX bicycle practicing. Submitted herewith are the results of our findings along
with recommendations for grading.
' 1.0 Site Suitability: The site is part of a 3.69 -acre (net) residential parcel with a naturally
contoured backyard well suited for the proposed creation of a practice track with very
' minimal grading. The proposed grading is feasible from a geotechnical standpoint
provided the recommendations contained herein are incorporated into the final design and
' construction of the project.
1.1 Structures: No structures are proposed for this phase of site development. An existing
' single family residence presently occupies the site, and is not to be altered in any fashion
as part of this development effort. As a result, no recommendations are necessary with
respect to structural design or construction. The proposed grading will not provide support
for structures of any kind.
' 1.2 Other Site Conditions: The area proposed for grading is presently a residential yard
covered with weeds of various kinds and some typical residential -type trees. The surface
' slopes towards the south and southeast, creating a contoured "bowl' very
25759 Jefferson Avenue, Murrieta, California 92562 • Phone: (951) 8349000 • fax: (951)8349001
Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 2
conducive to a track layout. Maximum relief within the proposed track area is on the order
of 60 feet in a distance of 300 feet. No structures are located in the area to be graded.
Access to the track will be via the existing residential driveway.
2.0 Site Review & Geotechnical Investigation: Based on our field reconnaissance, it
appears that a mantle of residual soils, colluvium and alluvium mantles the older Pauba
Formation bedrock. The soils exposed at the surface are mostly silty to clayey sands
and considered suitable for the proposed grading.
Since no structures are proposed and only minor grading, with small slopes (5' +/-
max.), mostly at inclinations of 3:1 and shallower are planned, it is our opinion that a
subsurface investigation is not warranted and would be a waste of the owners
resources. It is also considered of no practical value to include a regional geology
dissortation together with possible seismic effects and design considerations. As a
result, this letter is essentially limited to providing recommendations for the proposed
earthwork, with the consideration that the area being developed is to be used for a
bicycle riding track, and that the potential geotechnical effects on neighboring properties
is nil.
3.0 Earthwork Recommendations
3.1 General: The grading recommendations presented in this report are intended for: 1) the
use of a bicycle riding track; and 2) the re -compaction of near -surface earth materials to
create earthen mounds to act as jumps within the track layout. The following
recommendations may need to be modified and/or supplemented during rough grading as
field conditions require.
3.2 Clearing: All roots, grasses, weeds, brush, trees and other deleterious materials should
be removed from the proposed grading areas before grading is performed. No discing or
mixing of organic material into the soils should be performed. Man-made objects
encountered should be overexcavated and removed from the work area.
3.3 Excavation Characteristics: Excavation and trenching within the colluvium and alluvium
is anticipated to be relatively easy.
3.4 Suitability of On -Site Materials as Fill: In general, the on-site earth materials expected
to be encountered are considered suitable to be used as fill. Fill materials should be free
' Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
' Page 3
of significant amounts of organic materials and/or debris. Fill materials should not contain
rocks greater than 6 -inches in maximum dimension. The following recommendations are
general in nature and are provided as guidelines only. Actual grading operations should
' be under the observation and testing of the geotechnical consultant of record to insure
compliance with the recommendations of this Geotechnical Feasibility Report.
t3.5 Grading Recommendations for All Areas:
1. All vegetation, including roots, should be removed from areas to be graded and not
' used in fills.
' 2. All encountered man-made materials such as irrigation piping, electrical conduits and
associated materials should be excavated and removed from the project area and
not used in fills.
' 3. All colluvium, alluvium and weathered bedrock in areas to receive fill shall be
scarified to a minimum depth 6 inches, moisture conditioned and recompacted prior
' to placement of compacted fill.
4. No recompaction of cut areas is considered necessary.
' 5. No density testing of cut areas is considered necessary.
6. All fill placed on areas prepared in accordance with #3 above, shall be compacted to
a minimum of 90 percent relative compaction. Maximum dry density and optimum
' moisture content for compacted materials should be determined according to ASTM
D 1557-02 procedures.
' 7. All fill slopes which are part of the mounds created for jumps shall be constructed at
slope ratios of 2:1 (horizontal:vertical). All cut and fill slopes along the sides of the
' track shall be constructed at slope ratios of 3:1 (horizontal: vertical), or shallower.
3.6 Structural Fill: All fill material, whether on-site material or import, should be accepted by
the Project Geotechnical Engineer and/or his representative before placement. All fill
should be free from vegetation, organic material, and other debris. No imported fill is
anticipated for this project. Approved fill material should be placed in horizontal lifts not
exceeding 6.0 to 8.0 -inches in thickness, and watered or aerated to obtain near -optimum
moisture content (within 2.0 percent of optimum). Each lift should be spread evenly and
should be thoroughly mixed to ensure uniformity of soil moisture. Structural fill should
' Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 4
meet a minimum relative compaction of 90 percent of maximum dry density based upon
ASTM 1557-02 procedures. Moisture content of fill materials should not vary more than
2.0 percent of optimum, unless approved by the Project Geotechnical Engineer.
' 3.7 Compaction Equipment: It is anticipated that fill compaction for the project will be
achieved by the use of a combination of rubber -tired and track -mounted heavy
construction equipment. Compaction by rubber -tired or track -mounted equipment, by
itself, may not be sufficient. Adequate hoses or water trucks should be available to
' provide sufficient moisture and dust control. The actual selection of equipment is the
responsibility of the contractor performing the work and should be such that uniform and
' proper compaction of the fill is achieved.
3.8 Shrinkage — Alluvium & Colluvium: There will be a material loss due to the clearing and
' grubbing operations. Shrinkage of alluvial and colluvial materials that are excavated and
replaced as compacted fill should be anticipated. It is estimated that the average
' shrinkage of these soils will be on the order of 15 percent, based on fill volumes when
compacted to a minimum of 90 percent relative compaction. A higher relative compaction
' would mean a larger shrinkage value.
3.9 Keyways: No keyways are required at the toe of fill slopes due to the nature of the
' project and the small slopes being created. Typical benching, resulting in fills being
placed on level grades is considered sufficient.
4.0 Observation and Testing: During grading, observation and testing should be conducted
by the Project Geotechnical Engineer and/or his representative to verify that the grading is
being performed according to the recommendations presented in this report. The Project
Geotechnical Engineer and/or his representative should observe the scarification and the
placement of fill and should take tests to verify the moisture content, density, uniformity
and degree of compaction obtained. Where testing demonstrates insufficient density,
' additional compaction effort, with the adjustment of the moisture content where necessary,
should be applied until retesting shows that satisfactory relative compaction has been
' obtained. The results of observations and testing services should be presented in a formal
finish grading report following completion of the grading operations. The presence of the
' Project Geotechnical Engineer and/or his representative will be for the purpose of
providing observations and field testing and will not include any supervision or directing of
Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 5
the actual work of the contractor or the contractor's employees or agents. Neither the
presence and/or the non -presence of the Project Geotechnical Engineer and/or his field
representative nor the field observations and testing shall excuse the contractor in any way
for defects discovered in the contractor's work.
5.0 Stability Evaluation of Cut and Fill Slopes: No proposed manufactured slopes are
large enough or steep enough to warrant slope stability evaluation. All fill and cut slopes
are to be constructed in substantial accordance with the plans, at slope ratios of 2:1 or
3:1 (horizontal to vertical) to heights of approximately 5 feet maximum. It is our opinion
that properly constructed cut and fill slopes at this inclination will possess gross and
surficial stability in excess of generally accepted minimum engineering criteria (Factor of
Safety at least 1.5) and will be suitable for their intended purpose.
6.0 Finish Lot Drainage Recommendations: The track surface is planned to provide cross -
slope surface gradients of 1%, or more, and will distribute normal drainage to flow over the
tops of the 3:1 slopes. Concentrations of surface water should be directed toward suitable
drainage facilities or energy dissipating devices. Ponding of surface water should not be
allowed other than at designed erosion control devices. Drainage off the property should
be provided in a non-erosive manner.
7.0 Supplemental Construction Observations and Testing: Any subsequent grading for
development of the subject property should be performed under engineering observation
and testing performed by EnGEN Corporation. Subsequent grading includes, but is not
limited to, any additional overexcavation of cut and/or cut/fill transitions, fill placement, and
excavation of temporary and permanent cut and fill slopes. If any of the observations and
testing to verify site geotechnical conditions is not performed by EnGEN Corporation,
liability for the safety and performance of the development is limited to the actual portions
of the project observed and/or tested by EnGEN Corporation.
8.0 Plan Review: Any changes to the project design as represented in this report, and any
grading plans for the proposed development should be provided for review by this office
to verify compatibility with site geotechnical conditions and conformance with the
recommendations contained in this report. If EnGEN Corporation is not accorded the
opportunity to make the recommended review, we will assume no responsibility for
misinterpretation of the recommendations presented in this report.
' Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 6
9.0 Closure
This report has been prepared for use by the parties or project named or described in this
document. It may or may not contain sufficient information for other parties or purposes.
tIn the event that changes in the assumed nature, design, or location of the proposed
project as described in this report are planned, the conclusions and recommendations
contained in this report will not be considered valid unless the changes are reviewed and
the conclusions and recommendations of this report are modified or verified in writing.
' This study was conducted in general accordance with the applicable standards of our
profession and the accepted geotechnical engineering principles and practices at the time
this report was prepared. No other warranty, implied or expressed beyond the
representations of this report, is made. Although reasonable effort has been made to
' obtain information regarding the geotechnical and subsurface conditions of the site,
limitations exist with respect to the knowledge of unknown regional or localized off-site
' conditions that may have an impact at the site. The recommendations presented in this
report are valid as of the date of the report. However, changes in the conditions of a
' property can occur with the passage of time, whether they are due to natural processes or
to the works of man on this and/or adjacent properties. If conditions are observed or
information becomes available during the design and construction process that are not
' reflected in this report, EnGEN Corporation should be notified so that supplemental
evaluations can be performed and the conclusions and recommendations presented in
' this report can be modified or verified in writing. Changes in applicable or appropriate
standards of care or practice occur, whether they result from legislation or the broadening
of knowledge and experience. Accordingly, the conclusions and recommendations
presented in this report may be invalidated, wholly or in part, by changes outside of the
' control of EnGEN Corporation which occur in the future.
Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 7
Thank you for the opportunity to provide our services. If we can be of further service or should
you have questions regarding this report, please do not hesitate to contact this office at your
convenience.
Because of our involvement in the project to date, we would be pleased to discuss engineering
testing and observation services during construction operations that may be applicable on the
project.
Respectfully submitted,
EnGEN Corporation a fEESS/n..
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Distribution: (2) Addressee
(1) City of Temecula
FILE: EnGEN\ReporbnglGFSV3903-GFS Sipkoi BMX Track
Mr. & Mrs. Rick Sipkoi
Project Number: M3903 -GFS
May 2010
Page 8
DRAWINGS
s
ONE COMPLETE JUMP ONE COMPLI
30' so 20' so 30'
MOUND SEPARATION TAKE– BETWEEN JUMPS MOUND SEPARATION TAKE–
MOUND
'r+ PaE' ZONE ZFF ONE O ZONE
4' TO 5' TYP. pIRECTION OF TRAVEL
(VARIES)
TYPICAL SECTION THROUGH JUMPS
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• WIDTH e�-.
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TYPICAL SMP AT UPPER SECTION .�
NTS
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WIDTH A! T
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TYPICAL SANDBAGS
(2 HIGH)
TYPIrAI I-,ANIf1R0(, nFTAII
SILT nFICE-WOVEN FLIER FABRIC MATERIAL
(SEIMW TO STAKE WH 4 STAPLES)
It
■ Y NOW SUIS (OR EOIMN ENT)
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sACIOU. NO COIPACr THE DWAVAIEO salt IN
TRENCH AND ON BOM SM OF FLIER FABRIC
FLOW ,� DISRMED O M M
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10.79'
am,
FOR ENO STARE, FENCE FANK SWILL
E FOLDED AROUND TWO STAKES ONE
FIEI TURN AND SEMM WEN FOUR
TYPICAL SILT FENCE
Jer roux F rvice Aler ENGINEERS NOTE,
C3 lIA PRWAII I_NGINEER SIGNING THESE PLANS IS
k[' fP �NSIPI 1 I OR ASSURING THE ACCURACY OF DESIGN
CALL TOLL FREE AND ACC( F,IAHILITY OF THE WORK HEREON. IN THE
EVEN f 01 111` ,r_;REPANCIES ARISING AFTER COUNTY
M-227 -2600 APPP,0VA1- t4,'
DURING CONSTRUCTION, THE PRIVATE
LNGINI.FR `1 MI BE RESPONSIBLE FOR DETERMINING
AN A(.(.[ PlAiii L SOLATION AND REVISING THE PLANS
FOR APPRCVAI BY THE CITY.
TWO WORKING DAYS BEFORE YOU DIG
It NOTE:
NO INTERCEPTOR DRAIN
H/5 2' MIN REQUIRED FOR SLOPES 3:1
OR FLATTER
10' MAX REQb
INTERCEPTOR DRAIN
12" MIN
2 (MIN.)
�1
NATURAL GRADE
FINISH GRADE -
TYPICAL BROW DITCH/SETBACKS
NTS
X86"20'44"
R=48.00'
L=72.34'
iV69.
'_US= -GRACE COURr
j
N87'33'3_0"W
F- ----7 10 ----------
.80'
68' 52' 47"
R=48.00'
L= 57.7 1 '
TYPICAL EARTHEN
V—DRAIN DETAIL
NTS
L0
1" 30' r
I;i:izm
2
-� 1
BOTTOM
GRAPHIC SCALE
60 90 120
Civil Engineers - RCE 11873
General Conductors -Lim 378242
BRATEIVE 25759JefeaonAve.
CON S TRUCHON & Murrieta, CA 92562
_,GNGMERING (951)834-9009
(951) 834-9007 (FAV���'
DATE
BY
REVISIONS
DATE ACC'DI
SCALE
DESIGNED BY
DRAWN BY
CHECKED BY
RECOMMENDED BY: DATE:
ACCEPTED BY: ENGN� & DIRIIXTDR OF S`Qmb
GREG BUTLER
R.C.E. No, 47109
CITY 0 F T E M E C U LA
DEPARTMENT OF PUBLIC WORKS
Drawl
"� No.
OB
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G-2
HORIZONTAL
Plans Pr"mrsd Under The Supervision Of
Date:
OSBJORN BRATENE
R.C.E. No. 21873
PRECISE GRADING PLAN
SIPKOI BMX TRACK
33239 SUSAN GRACE COURT
TEMECULA, CA
1"=30'
N/A
SHEET 2 of 2
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